Apparatus for controlling compressor, control system for compressor and method for controlling compressor

ABSTRACT

The present disclosure relates to a compressor control apparatus, a compressor control system, and a compressor control method for controlling the switching operation of a plurality of switching modules according to a preset control criterion to discharge residual charge remaining in an electrolytic capacitor.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.10-2018-0088123, filed on Jul. 27, 2018, the contents of which isincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a compressor control apparatus forcontrolling a motor of a compressor, a compressor control system, and acompressor control method.

2. Description of the Conventional Art

The technology underlying the present disclosure relates to a controlapparatus (inverter) for controlling an electric compressor.

In an electric vehicle using an electric compressor, it is required todischarge residual charge remaining in the electric compressor in orderto prevent electric shock on a human body due to high voltage when anaccident or other emergency occurs.

In case of discharging residual charge in the control of the electriccompressor controlling an inverter in the related art, a high voltagedrawn into the electric compressor is cut off by a high voltagedistribution unit (HPDU), however, in order to remove charge remainingin an electrolytic capacitor when the power of the electric motor is cutoff by the HPDU, a power device is separately configured in a PCB todischarge the residual charge of the electrolytic capacitor. In otherwords, a separate discharge element for discharging the residual chargeis provided, and when such a discharge element is provided, the cost ofmanufacturing and design increases, and design constraints also increasesince the amount of space used increases. Even though the power deviceis pursued to be miniaturized, it has been required to minimize oreliminate the power device due to the characteristics of the inverterfor an electric compressor having a large space limitation. In addition,due to the safety problem, the discharge of the residual charge must beperformed in a state where the power supply is cut off. However, due tothe above structural/design limitations, the discharge control itselfmay not be performed safely and accurately.

In other words, in the related art, in order to remove the residualcharge remaining in the electrolytic capacitor when the power of theelectric compressor is cut off, a power device is separately configuredin a PCB to discharge the residual charge of the electrolytic capacitor.The provision of such a discharge element has structural/economiclimitations, and has caused a problem that thesafety/accuracy/reliability of the discharge control cannot beguaranteed.

SUMMARY OF THE INVENTION

An aspect of the present disclosure is to overcome the limitations ofthe related art as described above.

In other words, the present disclosure provides a compressor controlapparatus, a compressor control system, and a compressor control methodcapable of overcoming the limitations of the related art as describedabove.

Specifically, the present disclosure provides a compressor controlapparatus, a compressor control system, and a compressor control methodcapable of discharging residual charge stored in a control apparatus forcontrolling a compressor after the operation of the compressor isstopped.

In addition, the present disclosure provides a compressor controlapparatus, a compressor control system, and a compressor control methodcapable of appropriately and safely discharging the residual charge.

In order to solve the foregoing problems, a compressor controlapparatus, a compressor control system, and a compressor control methodaccording to the present disclosure may have technical features in whichthe switching operation of a plurality of switching modules iscontrolled according to a preset control criterion to discharge residualcharge remaining in an electrolytic capacitor.

Specifically, a discharge path may be formed through the switchingoperation of the plurality of switching modules, thereby discharging theresidual charge through the discharge path.

In other words, a compressor control apparatus, a compressor controlsystem, and a compressor control method according to the presentdisclosure may form a discharge path between the electrolytic capacitorand the motor through the plurality of switching modules so as todischarge the residual charge through the formed discharge path as asolution.

Through the foregoing solution, a compressor control apparatus, acompressor control system, and a compressor control method according tothe present disclosure may discharge the residual charge through thedischarge path so as to discharge the residual charge safely andappropriately without any additional discharge element, thereby solvingthe above-described problems.

The above technical features may be embodied in a compressor controlapparatus, a compressor control system, and a compressor control methodfor controlling the operation of a compressor through an inverter unitthat applies operating power to the motor through the switchingoperation of a plurality of switching modules, and the presentdisclosure may provide a compressor control apparatus, a compressorcontrol system, and a compressor control method using the foregoingtechnical features as a solution to the problems.

In order to solve the foregoing problems with the above technicalfeatures, a compressor control apparatus according to an embodiment ofthe present disclosure may include a cutoff unit configured to interruptpower received from an external power source, an input unit configuredto input power from the external power source through the cutoff unit,an inverter unit configured to convert the input power to operatingpower for operating a motor of a compressor through a plurality ofswitching modules to output the operating power to the motor, and acontrol unit configured to control the inverter unit to control theconversion and output of the operating power, wherein when the operationof the motor is stopped, the control unit controls the switchingoperation of the plurality of switching modules according to a presetcontrol criterion to discharge residual charge stored in the input unit.

Furthermore, in order to solve the foregoing problems with the abovetechnical features, a compressor control system according to anembodiment of the present disclosure may include a motor drivencompressor, and a control apparatus comprising a plurality of switchingmodules configured to convert power input from an external power sourceto operating power for operating the motor to output the operating powerto the motor so as to control the switching operation of the pluralityof switching modules to control the operation of the motor, wherein thecontrol apparatus controls the switching operation of two or morespecific switching modules among the plurality of switching modulesafter the operation of the motor is stopped to discharge residual chargestored in the control apparatus.

Moreover, in order to solve the foregoing problems with the abovetechnical features, there is provided a method of controlling acompressor control apparatus including a cutoff unit configured tointerrupt power received from an external power source, an input unitconfigured to input power from the external power source through thecutoff unit, an inverter unit configured to convert the input power tooperating power for operating a motor of a compressor through aplurality of switching modules to output the operating power to themotor, and a control unit configured to control the inverter unit so asto control the conversion and output of the operating power, and themethod may include cutting off power input from the external powersource, determining a discharge condition based on an operation state ofthe motor, controlling the plurality of switching modules according to apreset control criterion to perform the discharge control of residualcharge stored in the input unit, and stopping the discharge control.

The compressor control apparatus, the compressor control system, and thecompressor control method according to the present disclosure asdescribed above may be applied to and implemented on a compressorcontrol apparatus provided in a compressor, for instance, an inverterapparatus for controlling a motor of a compressor, a compressorincluding the same, or a control method for the compressor. However,technologies disclosed herein are not limited thereto, and may also beapplicable to all compressor control apparatuses, compressors,compressor control systems, and compressor control methods to which thetechnical concept of the present disclosure is applicable.

A compressor control apparatus, a compressor control system, and acompressor control method according to the present disclosure may form adischarge path through the switching operation of a plurality ofswitching modules, thereby having an effect of discharging the residualcharge through the discharge path.

In other words, a compressor control apparatus, a compressor controlsystem, and a compressor control method according to the presentdisclosure may discharge the residual charge through the discharge path,thereby having an effect of safely and appropriately discharging theresidual charge without any additional discharge element.

Furthermore, a compressor control apparatus, a compressor controlsystem, and a compressor control method according to the presentdisclosure may safely and appropriately discharge the residual chargethereby having an effect preventing the internal burnout of a compressorand a control apparatus that controls the compressor due to the residualcharge.

Moreover, a compressor control apparatus, a compressor control system,and a compressor control method according to the present disclosure maydischarge residual charge according to an input state of external powersource, an operation state of a motor, and a discharge state of theresidual charge, thereby having an effect of accurately performing thedischarge of residual charge, and reducing loss due to an unnecessaryswitching operation.

As a result, a compressor control apparatus, a compressor controlsystem, and a compressor control method according to the presentdisclosure may reliably and accurately discharge residual charge withoutany additional discharge element, thereby having an effect of improvingthe limitations of the related art as well as increasing stability,accuracy, ease of use, utility, usefulness and reliability of electriccompressor control using an inverter.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a configuration view showing a configuration of a compressorcontrol apparatus according to the present disclosure.

FIG. 2 is a configuration view showing a specific circuit configurationof a compressor control apparatus according to the present disclosure.

FIG. 3 is a circuit configuration view showing current flow according todischarge control of a compressor control apparatus according to thepresent disclosure.

FIG. 4 is a graph showing a result of discharge control of a compressorcontrol apparatus according to the present disclosure.

FIG. 5 is a flowchart showing a control process of a compressor controlsystem according to the present disclosure.

FIG. 6 is a flowchart showing a flow of a compressor control apparatusaccording to the present disclosure.

FIG. 7 is a flowchart showing a specific flow of a compressor controlapparatus according to the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention disclosed herein may be applicable to a compressor controlapparatus, a compressor control system, a compressor control method, anda compressor to which such a technology is applied. However, theinvention disclosed in this specification is not limited thereto, butmay also applicable to all existing compressor control apparatuses,compressor control systems, compressors and compressor control methods,motor control apparatuses, motor operating apparatuses, inverterapparatuses of controlling a motor, control methods of a motor controlapparatus, control methods of an inverter apparatus, control elements ofcontrolling a motor control apparatus and control methods thereof,control apparatuses of controlling an inverter apparatus, and controlmethods thereof, and the like, and more particularly, may be usefullyapplicable to a compressor control apparatus, a compressor controlsystem, and a compressor control method of controlling an electriccompressor.

It should be noted that technological terms used herein are merely usedto describe a specific embodiment, but not to limit the concept oftechnologies disclosed herein. Furthermore, unless particularly definedotherwise, technological terms used herein should be construed as ameaning that is generally understood by those having ordinary skill inthe art disclosed herein, and should not be construed too broadly or toonarrowly. Furthermore, if technological terms used herein are wrongterms unable to correctly express the concept of technologies disclosedherein, then they should be replaced by technological terms that areproperly understood by those skilled in the art. In addition, generalterms used in the present specification should be construed based on thedefinition of dictionary, or the context, and should not be construedtoo broadly or too narrowly.

Furthermore, a singular representation used in the present specificationmay include a plural representation as far as it represents a definitelydifferent meaning from the context. In the present specification, theterms “comprising” and “including” should not be construed tonecessarily include all of the elements or steps disclosed herein, andshould be construed not to include some of the elements or stepsthereof, or should be construed to further include additional elementsor steps.

In describing technologies disclosed herein, moreover, the detaileddescription will be omitted when specific description for publicly knowntechnologies to which the invention pertains is judged to obscure thegist of the present invention. In addition, it should be noted that theaccompanying drawings are merely illustrated to easily explain thetechnological concept disclosed herein, and therefore, they should notbe construed to limit the technological concept by the accompanyingdrawings.

First, a compressor control apparatus (hereinafter, referred to as acontrol apparatus) according to the present disclosure will bedescribed.

The control apparatus denotes a control apparatus for controlling theoperation of the compressor.

The control apparatus may be a control apparatus for supplying operatingpower to the motor of the compressor and controlling the operation ofthe compressor.

The control apparatus may be an apparatus for controlling the driving ofthe compressor to control the operation of the compressor.

The control apparatus may be an apparatus for controlling the motorusing an inverter method.

In other words, the control apparatus may be an inverter that controlsthe driving of the compressor, or an apparatus including the inverter.

The control apparatus may control the operation of the motor bycontrolling the switching operation of the inverter and controlling theoperating power applied to the motor.

The control apparatus may control the operating power through thecontrol of the switching operation to control the operation of themotor, thereby controlling the operation of the compressor.

As illustrated in FIG. 1, a control apparatus 100 includes a cutoff unit10 for interrupting power input from an external power source 1, aninput unit 20 for receiving power from the external power source 1through the cutoff unit 10, an inverter unit 30 for converting thereceived power into operating power for operating a motor 200 of acompressor (C) through a plurality of switching modules to output theoperating power to the motor 200, and a control unit 40 for controllingthe inverter unit 30 to control the conversion and output of theoperating power.

The control apparatus 100 controls the switching operation of theplurality of switching modules included in the inverter unit 30 by thecontrol unit 40 to control the conversion and output of the operatingpower converted through the switching operation, thereby controlling theoperation of the motor 200.

In the control apparatus 100 including the cutoff unit 10, the inputunit 20, the inverter unit 30 and the control unit 40 as describedabove, the control device 40 controls the switching operation of theplurality of switching modules according to a preset control criterionto discharge residual charge stored in the input unit 20 when theoperation of the motor 200 is stopped.

In other words, when the operation of the motor 200 is stopped, thecontrol apparatus 100 may control the switching operation of theplurality of switching modules according to the control criterion,thereby discharging the residual charge stored and remained in the inputunit 200 during the operation of the motor 200.

The specific configuration of the control apparatus 100 may be as shownin FIG. 2.

The cutoff unit 10 may be a high voltage power distribution unit (HPDU)for distributing high voltage power.

The cutoff unit 10 is closed at normal times, and open when sensing ahigh voltage above a predetermined reference level to cut off powerinput from the external power source 1.

For example, when an accident occurs in the external power source 1 togenerate a high voltage above predetermined reference level, it isdetected to open, thereby cutting off power input from the externalpower source 1 to the control apparatus 100.

When a high voltage above the predetermined reference level is inducedfrom the external power source 1 or a high voltage above thepredetermined reference level is generated in the control apparatus 100,the cutoff unit 10 is open to separate the control apparatus 100 fromthe external power source 1.

The cutoff unit 10 may be controlled by the control unit 40 or a controlelement at an outside of the control apparatus 100.

The input unit 20 may receive direct current (DC) power or alternatingcurrent (AC) power from the external power source 1 through the cutoffunit 10.

When power input to the input unit 10 is the DC power, the externalpower source 1 may be a battery for storing the DC power or a powersupply element for supplying the DC power.

When power input to the input unit 10 is the AC power, the externalpower source 1 may be power conversion element for converting the DCpower to the AC power or a power supply element for supplying the ACpower.

The input power may preferably be the DC power.

The input unit 20 may include a smoothing capacitor for smoothing theinput power.

The smoothing capacitor may be a DC link capacitor that reduces theripple of the input power to smooth it in the form of DC power.

The smoothing capacitor may be an electrolytic capacitor.

The input unit 20 may store and smooth the DC power input from theexternal power source 1 through the cutoff unit 10 in the smoothingcapacitor formed of the electrolytic capacitor.

The input unit 20 is connected to the inverter unit 30 to transfer theDC power smoothed through the smoothing capacitor to the inverter unit30.

The inverter unit 30 is connected to the motor 200 to convert the DCpower received through the input unit 20 to the operating power andoutput it to the motor 200.

Here, the motor 200 may be a three-phase motor that drives thecompressor (C), and the operating power may be in the form ofthree-phase AC power.

The inverter unit 30 may convert the DC power into the operating powerin the form of the AC power and output it to the motor 200.

The inverter unit 30 may convert the DC power into three-phase AC powerthrough the switching operation of the plurality of switching modules 31to 36.

The plurality of switching modules 31 to 36 may be preferably insulatedgate bipolar transistor (IGBT) modules.

The switching operation of the plurality of switching modules 31 to 36may be controlled by the control unit 40.

The plurality of switching modules 31 to 36 may receive a control signalfor the switching operation from the control unit 40 to perform aswitching operation and convert the DC power to the AC power accordingto the control signal.

The plurality of switching modules 31 to 36 may include three pairs ofswitching modules 31-34, 32-35, 33-36, in which two switching modulesare connected in series, as shown in FIG. 2.

The plurality of switching modules 31 to 36 including the three pairs ofswitching modules 31-34, 32-35, 33-36 may include first through thirdupper arm switching modules 30 a (31 to 33) connected to an anode end ofthe input unit 20, and first through third lower arm switching modules30 b (34 to 36) connected in series to the upper arm switching modules30 a (31 to 33), respectively, and connected to a cathode end of theinput unit 20.

Here, each of the three pairs of switching modules 31-34, 32-35, 33-36may constitute each phase of the three-phase power output to the motor200.

For instance, the first pair 31-34 may be a U-phase, the second pair32-35 may be a V-phase, and the third pair 33-36 may be a W-phase.

The plurality of switching modules 31 to 36 in which the upper armswitching module 30 a (31 to 33) and the lower arm switching module 30 b(34 to 36) connected to each other in pairs, respectively, may becontrolled by the control unit 40 to output the operating power to themotor 200.

In other words, the inverter unit 30 including the plurality ofswitching modules (31 to 36) may be controlled by the control unit 40.

In the inverter unit 30, the switching operation is controlled by thecontrol unit 40 to control and the operation of the motor 200.

The inverter unit 30 may control the operating power output to the motor200 and applied to the motor 200 through the control of the switchingoperation to control the operation speed of the motor 200.

Here, the operation speed may denote a rotation speed of the motor 200.

The operation speed may also be replaced with an operation frequency atwhich the motor 200 operates or the number of revolutions of the motor200 associated with the operation speed.

Hereinafter, for convenience of explanation, the embodiment will bedescribed around the operation speed, but the implementation of thepresent disclosure may be implemented in a manner of replacing theoperation speed with the operation frequency or the rotation speed.

The control unit 40 for controlling the switching operation to controlthe operation of the motor 200 may detect the voltage and current of themotor 200, and measure the operation speed of the motor 200 based on thedetected motor voltage and the motor current to control the switchingoperation according to the measured operation speed.

The control unit 40 may detect the motor voltage and the motor currentapplied to the motor 200 according to the switching operation, andmeasure the operation speed based on the motor voltage and the motorcurrent.

The control unit 40 may generate a control signal for controlling theswitching operation according to the operation speed, and apply thecontrol signal to the inverter 30 to control the switching operation.

The control unit 40 may determine at least one of a command voltage forthe motor voltage, a command current for the motor current, a speedcommand for the operation speed, and a frequency command for theswitching frequency according to the operation speed, and generate thecontrol signal according to the determination result.

In other words, the control unit 40 may determine at least one thecommand voltage, the command current, the speed command, the speedcommand, and the frequency command based on at least one of thedetection result of detecting the motor voltage and the motor current,and the measurement result of measuring the operation speed, andgenerate the control signal according to the determination result,thereby controlling at least one of the motor voltage, the motorcurrent, the operation speed, and the switching frequency.

As described above, the control unit 40 may control at least one of themotor voltage, the motor current, the operation speed and the switchingfrequency through the control of the switching operation, therebycontrolling the operation of the motor 200.

The control unit 40 may include a first control unit 41 for controllingthe cutoff unit 10 and a second control unit 42 for controlling theinverter unit 30.

When the control unit 40 includes the first control unit 41 and thesecond control unit 42 as described above, the first control unit 41 maygenerate a control command for the control of the inverter unit 30 totransfer it to the second control unit 42, and the second control unit42 may generate the control signal according to the control commandreceived from the first control unit 41.

As described above, the control unit 40 that controls the switchingoperation of the inverter unit 30 to control the conversion and outputof the operating power controls the switching operation of the pluralityof switching modules 31 to 36 according the control criterion todischarge the residual charge stored in the input unit 20 when theoperation of the motor 200 is stopped.

In other words, the control unit 40 controls the switching operation ofthe plurality of switching modules 31 to 36 to discharge the residualcharge remaining in the input unit 20 when the operation of the motor200 is stopped.

The control unit 40 may determine whether or not the operation of themotor 200 is stopped while the cutoff unit 10 is open, and controls theswitching operation to discharge the residual charge when the operationof the motor is stopped.

In other words, only when the operation of the motor 200 is stopped in astate where the cutoff unit 10 is open and power input to the input unit20 from the external power source 1 is cut off, the control unit 40 maycontrol the switching operation to discharge the residual charge.

As described above, the switching operation may be controlled todischarge the residual charge in a state where the cutoff unit 10 isopen, and the operation of the motor 200 is stopped, thereby preventingthe residual charge from being discharged toward the external powersource 1 and allowing power to be input from the external power source 1to the input unit 20 to prevent the power from being stored in the inputunit 20 in which the residual charge is being discharged.

In the control unit 40 that controls the switching operation todischarge the residual charge in a state where the cutoff unit 10 isopen and the operation of the motor 200 is stopped as described above,the first control unit 41 may transfer information on the cutoff stateof the cutoff unit 10 and the switching operation control to the secondcontrol unit 42 while the cutoff unit 10 is controlled to be open, andthe second control unit 42 may control the switching operation based onthe cutoff state and information on the switching operation controlreceived from the first control unit 41.

In other words, the second control unit 42 may determine whether theoperation of the motor 200 is stopped to control the switching operationonly when the information on the cutoff state of the cutoff unit 10 isreceived from the first control unit 41.

The control unit 40 may control the switching operation to discharge theresidual charge when the operation of the motor 200 is stopped for morethan a preset standby time period.

In other words, the control unit 40 may control the switching operationto discharge the residual charge when the operation stop of the motor200 has passed the standby time.

The standby time may be a period of time for which charge remaining inthe motor 200 is discharged immediately after the operation of the motor200 is stopped.

In other words, when the operation of the motor 200 is stopped for morethan the standby time, the control unit 40 may determine that chargeremaining in the motor 200 is discharged after the operation of themotor 200 is stopped so as to control the switching operation todischarge the residual charge.

The standby time may be a period of time for which the operation of themotor 200 is completely stopped.

For instance, it may be a period of time from the start of stopping theoperation speed of the motor 200 to a time point when the operationspeed is zero.

As described above, the control unit 40 may control the switchingoperation to discharge the residual charge after the operation of themotor 200 is completely stopped and charge remaining in the motor 200 isdischarged, thereby safely and accurately discharging the residualcharge remaining in the input unit 20.

The control unit 40 for discharging residual charge after the cutoffunit 10 is open, and the operation of the motor 200 is completelystopped and the charge remaining in the motor 200 is discharged, maycontrol the switching operation according to the control criterion todischarge the residual charge.

The control criterion may be a criterion for controlling two or more ofthe plurality of switching modules 31 to 36.

In other words, the control unit 40 may control switching operations oftwo or more of the plurality of switching modules 31 to 36 when theswitching operation is controlled to discharge the residual charge.

The control criterion may be a criterion for controlling the switchingoperation of two or more switching modules among the plurality ofswitching modules 31 to 36 to form a discharge path between the inputunit 20 and the motor 200.

In other words, the control unit 40 may control the switching operationof two or more of the plurality of switching modules 31 to 36 accordingto the control criterion to form the discharge path through which theresidual charge is discharged.

The control unit 40 that controls the switching operation according tothe control criterion may control the switching operation of any oneupper arm switching module in the switching modules 30 a connected to ananode end of the input unit 20, and one or more lower arm switchingmodules excluding a switching module connected to the upper armswitching module in the switching modules 30 b connected to a cathodeend of the input unit 20 among the plurality of switching modules 31 to36 to discharge the residual charge.

A specific example of controlling the switching operation according tothe control criterion will be described below with reference to FIG. 3.

According to a specific control example of the control unit 40, asillustrated in FIG. 3, it may be possible to control the switchingoperation of any one upper arm switching module connected to an anodeend of the input unit 20 among the plurality of switching modules 31 to36, and one or more lower arm switching modules other than the switchingmodule connected to the upper arm switching module among the switchingmodules 30 b connected to a cathode end of the input unit 20.

In other words, in this case, the control unit 40 may control the firstupper arm switching module 31 among the upper arm switching modules 30a, and the second lower arm switching module 35 and the third lower armswitching module 36 excluding the first lower arm switching module 34connected to the first upper arm switching module 31 among the lower armswitching modules 30 b.

At this time, the control unit 40 may control the switching operation toturn on the first upper switching module 31, the second lower armswitching modules 35 and the third lower arm switching module 36.

Furthermore, the control unit 40 may control the switching operation ofthe second upper arm switching module 32 among the upper arm switchingmodules 30 a, the first lower arm switching module 34 and the thirdlower arm switching module 36 excluding the second lower arm switchingmodule 35 connected to the second upper arm switching module 32 amongthe lower arm switching modules 30 b, and may also control the switchingoperation of the third upper arm switching module 33 among the upper armswitching modules 30 a, the first lower arm switching module 34 and thethird lower arm switching module 35 excluding the third lower armswitching module 36 connected to the third upper arm switching module 33among the lower arm switching modules 30 b.

The control unit 40 that controls the switching operation may controlthe switching operation of the upper arm switching module 30 a and thelower arm switching module 30 b to form the discharge path between theinput unit 20 and the motor 200 through the upper arm switching modules30 a and the lower arm switching modules 30 a, thereby discharging theresidual charge through the formed discharge path.

In other words, the control unit 40 that controls the switchingoperation may control the switching operation of any one upper armswitching module in the switching modules 30 a connected to an anode endof the input unit 20, and one or more lower arm switching modulesexcluding a switching module connected to the upper arm switching modulein the switching modules 30 b connected to a cathode end of the inputunit 20.

Describing the operation with reference to an example illustrated inFIG. 3, the control unit 40 may control the switching operation of thefirst upper arm switching module 31 in the upper arm switching modules30 a, and the second lower arm switching module 35 and the third lowerarm switching module 36 excluding the first lower arm switching module34 connected to the upper arm switching module 31 in the lower armswitching modules 30 b to be turned on to form the discharge pathconnected through [an anode end of the input unit 20—the first upper armswitching module 31—the motor 200—the second lower arm switching module35 and the third lower arm switching module 36—a cathode end of theinput unit 200], thereby discharging the residual charge stored in theinput unit 20 through a loop of [the anode end of the input unit 20—thefirst upper arm switching module 31—the motor 200—the second lower armswitching module 35 and the third lower arm switching module 36—thecathode end of the input unit 200].

In other words, the control unit 40 may form the discharge path betweenthe control apparatus 100 and the motor 200 through the turn-on controlof at least two switching modules among the plurality of switchingmodules 31 to 36, thereby discharging the residual charge through thedischarge path.

As described above, the control unit 40 may control the switchingmodules among the plurality of switching modules 31 to 36 to be turnedon according to the control criterion to form the discharge path betweenthe control apparatus 100 and the motor 200, thereby discharging theresidual charge in the control apparatus 100 and the motor 200 withoutany additional discharging element.

In this manner, the control unit 40 that controls the switchingoperation according to the control criterion, may control the switchingoperation for a preset discharge time period to discharge the residualcharge.

The discharge time period may be a period of time for which the residualcharge is discharged through the discharge path.

In other words, the control unit 40 may control the switching operationto discharge the residual charge for the discharge time period.

The discharge time period may be one second, for example.

As described above, the discharge control result of the control unit 40for controlling the discharge of the residual charge may be as shown inFIG. 4.

As illustrated in FIG. 4, when the cutoff unit 10 is open and theoperation of the motor 200 is stopped (t1), the control unit 40 maystart the discharge control of the residual charge, and control theturn-on of at least two switching modules among the plurality ofswitching modules 31 to 36 for the discharge time period (t3−t2) afterthe operation stop of the motor 200 has passed the standby time (t2)such that the residual charge flows through the discharge path formedthrough the switching operation in a direction of the motor 200 for thedischarge time period (motor current), thereby discharging the residualcharge through the discharge path for the discharge time period.

After the residual charge is completely discharged for the dischargetime period (t3), the control unit 40 may stop the discharge control toprevent the unnecessary switching operation of the plurality ofswitching modules 31 to 36.

In other words, when the discharge time period (t3) has passed to endthe discharge of the residual charge, the control unit 40 may stop thecontrol of the switching operation to prevent the loss and burnout ofthe plurality of switching modules 31 to 36 according to the switchingoperation.

Hereinafter, a compressor control system (hereinafter, referred to as acontrol system) according to the present disclosure will be described,and its redundant described above in the control apparatus 100 will beomitted as much as possible.

The control system denotes a system for controlling the operation of thecompressor.

The control system may be a control system for supplying operating powerto the motor of the compressor to control the operation of thecompressor.

The control system may be a control system that controls the motor in aninverter manner.

The control system may control the switching operation of the inverterto control operating power applied to the motor, thereby controlling theoperation of the motor.

The control system may control the operating power through the controlof the switching operation to control the operation of the compressor,thereby controlling the driving of the compressor.

The control system may control the driving of the compressor includingthe control apparatus 100 described above.

As illustrated in FIG. 2, the control system includes a controlapparatus 100 including a compressor (C) operated by a motor 200, and aplurality of switching modules 31 to 36 for converting power input froman external power source 1 to operating power for operating the motor200 to output the converted power to the motor 200 so as to control theswitching operation of the plurality of switching modules 31 to 36 tocontrol the operation of the motor 200.

Here, the control apparatus 100 may be the control apparatus 100described above.

In the control system, after the operation of the motor 200 is stopped,the control apparatus 100 controls the switching operation of at leasttwo specific switching modules among the plurality of switching modules31 to 36 to discharge residual charge stored in the control apparatus100.

In other words, the control system controls the switching operation todischarge the residual charge when the operation of the motor 200 isstopped.

As illustrated in FIG. 2, the control apparatus 100 may include a cutoffunit 10 for interrupting power input from the external power source 1,an input unit 20 for receiving power from the external power source 1through the cutoff unit 10, an inverter unit 30 for converting thereceived power into the operating power through the plurality ofswitching modules 31 to 36 to output the operating power to the motor200, and a control unit 40 for controlling the inverter unit 30 tocontrol the conversion and output of the operating power.

The control apparatus 100 may also be a control element having aconfiguration different from that of the control apparatus 100 describedabove.

The control apparatus 100 for controlling the switching operation tocontrol the operation of the motor 200 may detect the voltage andcurrent of the motor 200, and measure the operation speed of the motor200 based on the detected motor voltage and the motor current to controlthe switching operation according to the measured operation speed.

The control apparatus 100 may detect the motor voltage and the motorcurrent applied to the motor 200 according to the switching operation,and measure the operation speed based on the motor voltage and the motorcurrent.

The control apparatus 100 may generate a control signal for controllingthe switching operation according to the operation speed, and apply thecontrol signal to the inverter unit 30 to control the switchingoperation.

The control apparatus 100 may determine at least one of a commandvoltage for the motor voltage, a command current for the motor current,a speed command for the operation speed, and a frequency command for theswitching frequency according to the operation speed, and generate thecontrol signal according to the determination result.

In other words, the control apparatus 100 may determine at least one thecommand voltage, the command current, the speed command, the speedcommand, and the frequency command based on at least one of thedetection result of detecting the motor voltage and the motor current,and the measurement result of measuring the operation speed, andgenerate the control signal according to the determination result,thereby controlling at least one of the motor voltage, the motorcurrent, the operation speed, and the switching frequency.

As described above, the control apparatus 100 may control at least oneof the motor voltage, the motor current, the operation speed and theswitching frequency through the control of the switching operation,thereby controlling the operation of the motor 200.

As described above, the control apparatus 100 that controls theswitching operation of the inverter unit 30 to control the conversionand output of the operating power controls the switching operation ofthe plurality of switching modules 31 to 36 according the controlcriterion to discharge the residual charge when the operation of themotor 200 is stopped.

Here, the residual charge may be charge in which power stored in theinput unit 20 remains.

In other words, the control apparatus 100 controls the switchingoperation of the plurality of switching modules 31 to 36 to dischargethe residual charge remaining in the input unit 20 after the operationof the motor 200 is stopped.

The control apparatus 100 may include the cutoff unit 10, which isclosed at normal times, and open when sensing a high voltage above apredetermined reference level to cut off power input from the externalpower source 1, thereby controlling the switching operation to dischargethe residual charge while the cutoff unit 10 is open.

In other words, only when the operation of the motor 200 is stopped in astate where the cutoff unit 10 is open and power input to the input unit20 from the external power source 1 is cut off, the control apparatus100 may control the switching operation to discharge the residualcharge.

The control apparatus 100 may stop the operation of the motor 200, andcontrol the switching operation to discharge the residual charge after apreset standby time has passed.

In other words, the control apparatus 100 may control the switchingoperation to discharge the residual charge when the operation of themotor 200 is stopped for more than the standby time.

The control apparatus 100 may control the switching operation accordingto the control criterion to discharge the residual charge.

The control criterion may be a criterion for controlling two or more ofthe plurality of switching modules 31 to 36.

In other words, the control apparatus 100 may control switchingoperations of two or more of the plurality of switching modules 31 to 36when the switching operation is controlled to discharge the residualcharge.

The control criterion may be a criterion for controlling the switchingoperation of two or more switching modules among the plurality ofswitching modules 31 to 36 to form a discharge path between the inputunit 20 and the motor 200.

In other words, the control apparatus 100 may control the switchingoperation of two or more of the plurality of switching modules 31 to 36according to the control criterion to form the discharge path throughwhich the residual charge is discharged.

The control unit 100 may control the switching operation of any oneupper arm switching module in the switching modules 30 a disposed at oneside of the plurality of switching modules 31 to 36, and one or morelower arm switching modules excluding a switching module connected tothe upper arm switching module in the switching modules 30 b disposed atthe other side thereof to discharge the residual charge.

The control apparatus 100 may control the switching operation of any oneupper arm switching module in the switching modules 30 a connected to ananode end of the input unit 20, and one or more lower arm switchingmodules excluding a switching module connected to the upper armswitching module in the switching modules 30 b connected to a cathodeend of the input unit 20 among the plurality of switching modules 31 to36 to discharge the residual charge.

As illustrated in FIG. 3, the control apparatus 100 may be possible tocontrol the switching operation of any one upper arm switching moduleconnected to an anode end of the input unit 20 among the plurality ofswitching modules 31 to 36, and one or more lower arm switching modulesother than the switching module connected to the upper arm switchingmodule among the switching modules 30 b connected to a cathode end ofthe input unit 20.

At this time, the control apparatus 100 may control the switchingoperation to turn on the first upper switching module 31, the secondlower arm switching modules 35, and the third lower arm switching module36.

The control apparatus 100 that controls the switching operation maycontrol the switching operation of the upper arm switching module 30 aand the lower arm switching module 30 b to form the discharge pathbetween the input unit 20 and the motor 200 through the upper armswitching modules 30 a and the lower arm switching modules 30 a, therebydischarging the residual charge through the formed discharge path.

In other words, the control apparatus 100 that controls the switchingoperation may control the switching operation of any one upper armswitching module in the switching modules 30 a connected to an anode endof the input unit 20, and one or more lower arm switching modulesexcluding a switching module connected to the upper arm switching modulein the switching modules 30 b connected to a cathode end of the inputunit 20.

In this manner, the control apparatus 100 that controls the switchingoperation according to the control criterion, may control the switchingoperation for a preset discharge time period to discharge the residualcharge.

The discharge time period may be a period of time for which the residualcharge is discharged through the discharge path.

In other words, the control apparatus 100 may control the switchingoperation to discharge the residual charge for the discharge timeperiod.

The control process of the control system of controlling the switchingoperation to discharge the residual charge as described above may becarried out in a sequence as shown in FIG. 5.

The control system may control the operation of the motor 200 by thecontrol apparatus 100 in a control process as shown in FIG. 5.

Here, the control process as shown in FIG. 5 may be carried out by thecontrol unit 40 of the control apparatus 100, and may be applicable tothe foregoing embodiment of the control unit 40 of the control apparatus100.

As illustrated in FIG. 5, the control apparatus 100 may open (P1) thecutoff unit 10 to prepare (P2) discharge control for discharging theresidual charge while cutting off power from being received from theexternal power source 1.

Here, the preparation (P2) for discharge control may be a process ofallowing the first control unit 41 that controls the opening of thecutoff unit 10 to transfer the cutoff state information of the cutoffunit 10 and a command for the execution of the discharge control to thesecond control unit 42 that controls the switching operation of theplurality of switching modules 31 to 36 so as to allow the secondcontrol unit 42 to prepare the switching operation.

Then, the control apparatus 100 may stop the operation of the motor 200(P3), and then determine whether or not the operation stop time of themotor 200 has passed the standby time period (P4), thereby controllingthe switching operation in accordance with the control criterion whenthe motor stops for more than the standby time period.

Here, when the operation of the motor 200 is not stopped or the standbytime has not passed after the operation of the motor 200 is stopped, thepreparation process of the discharge control (P2) may be repeated.

The control apparatus 100 may control the switching operation for thedischarge time period to discharge the residual charge for the dischargetime period after starting the discharge of the residual charge (P5) soas to stop the control of the switching operation after the dischargetime period has passed (P6), thereby stopping the discharge of theresidual charge (P7).

The control system for controlling the switching operation to dischargethe residual charge as described above may also control the switchingoperation in a process other than the control process as shown in FIG.5.

Hereinafter, a compressor control method (hereinafter, referred to as acontrol method) according to the present disclosure will be described,and its redundant described above in the control apparatus 100 and thecontrol system will be omitted as much as possible.

The control method may be a control method for controlling a compressor.

The control method may be a control method of a control apparatus forcontrolling the compressor.

The control method may be a control method of the control apparatus 100or the control system.

As illustrated in FIG. 2, the control method is a compressor controlmethod of the compressor control apparatus 100 including a cutoff unit10 for interrupting power input from an external power source 1, aninput unit 20 for receiving power from the external power source 1through the cutoff unit 10, an inverter unit 30 for converting thereceived power into operating power for operating a motor 200 of acompressor (C) through a plurality of switching modules 31 to 36 tooutput the operating power to the motor 200, and a control unit 40 forcontrolling the inverter unit 30 to control the conversion and output ofthe operating power, and as illustrated in FIG. 6, the control methodincludes cutting off power received from the external power source 1(S10), determining a discharge condition based on the operation state ofthe motor 200 (S20), controlling the plurality of switching modules 31to 36 based on a preset control criterion to perform the dischargecontrol of the residual charge stored in the input unit 20 (S30), andstopping the discharge control (S40).

The control method as shown in FIG. 6 may be carried out in a sequenceas shown in FIG. 7.

In the step (S10) of cutting off input power, the cutoff unit 10 may beoperated to be open so as to cut off power input from the external powersource 1.

The step (S20) of determining a discharge condition may determine thedischarge condition after the cutoff unit 10 is open in the step S10 ofcutting off the input power.

The discharge condition may be a condition for performing the dischargecontrol of the residual charge.

The discharge condition may be a condition for whether or not theoperation of the motor 200 is stopped or an operation stop time period.

In other words, the step (S20) of determining the discharge condition(S20) may determine whether or not the operation is stopped or theoperation stop time period.

The step (S20) of determining the discharge condition may includedetermining whether or not the operation is stopped (S21) anddetermining the operation stop time period (S22).

The step (S21) of determining whether or not the operation is stoppedmay determine whether or not the operation of the motor 200 is stopped.

The step (S21) of determining whether or not the operation is stoppedmay determine whether or not the operation speed of the motor 200 iszero to determine whether or not the operation is stopped.

The step (S22) of determining the operation stop time period may comparea time period for which the operation of the motor 200 is stopped withthe standby time period when it is determined that the operation of themotor 200 is stopped in the step (S21) of determining whether or not theoperation is stopped to determine whether or not the operation stop timeperiod has passed the standby time period.

The step (S22) of determining the operation stop time period maydetermine that the operation of the motor 200 is completely stopped whenthe operation stop time period of the motor 200 has passed the standbytime period.

The step (S30) of performing the discharge control may control theswitching operation of the plurality of switching modules 31 to 36 todischarge the residual charge when the operation stop time period of themotor 200 has passed the standby time period in the step (S20) ofdetermining the discharge condition.

The step (S30) of performing the discharge control may control theswitching operation of any one upper arm switching module connected toan anode end of the input unit 20 among the plurality of switchingmodules 31 to 36, and one or more lower arm switching modules other thanthe switching module connected to the upper arm switching module amongthe switching modules 30 b connected to a cathode end of the input unit20.

The step (S30) of performing the discharge control may control theswitching operation of the upper arm switching module 30 a and the lowerarm switching module 30 b to form the discharge path between the inputunit 20 and the motor 200 through the upper arm switching modules 30 aand the lower arm switching modules 30 a, thereby discharging theresidual charge through the formed discharge path.

The step S30 of performing the discharging control for discharging theresidual charge as described above may include controlling the switchingoperation of the plurality of switching modules 31 to 36 according tothe control criterion (S31) and maintaining the control of the switchingoperation for a preset discharge time period (S32).

The step (S31) of controlling the switching operation may control theswitching operation of any one upper arm switching module in theswitching modules 30 a connected to an anode end of the input unit 20,and one or more lower arm switching modules excluding a switching moduleconnected to the upper arm switching module in the switching modules 30b connected to a cathode end of the input unit 20 as described above.

The step (S32) of maintaining the discharge time period may perform thestep (S31) of controlling the switching operation for the discharge timeperiod.

The step (S40) of stopping the discharge control may stop the dischargecontrol after the execution of the step (S30) of performing thedischarge control.

Though a specific embodiment according to the present disclosure hasbeen described above, it will be apparent to those skilled in this artthat various modification may be made without departing from the scopeof the present invention. Therefore, the scope of the present disclosureshould not be limited to the described embodiments, but should bedetermined by the scope of the appended claims and equivalents thereof.

Although the present disclosure has been described with respect tospecific embodiments and drawings, the present disclosure is not limitedto those embodiments, and it will be apparent to those skilled in theart that various changes and modifications can be made from thedescription disclosed herein. Consequently, the concept of the presentdisclosure should be construed in accordance with the appended claims,and all the same and equivalent changes will fall into the scope of thepresent disclosure.

What is claimed is:
 1. A compressor control apparatus, comprising: acutoff unit configured to interrupt power input from an external powersource; an input unit configured to receive the power input from theexternal power source through the cutoff unit; an inverter unitconfigured to convert an input power supplied from the input unit to anoperating power for operating a motor of a compressor, the inverter unitcomprising a plurality of switching modules configured to perform aswitching operation to control an output of the operating power to themotor; and a control unit configured to, by controlling the inverterunit, control a conversion of the input power to the operating power andthe output of the operating power, wherein the control unit isconfigured to, based on an operation of the motor being stopped, controlthe switching operation of the plurality of switching modules accordingto a preset control criterion to thereby discharge a residual chargestored in the input unit.
 2. The compressor control apparatus of claim1, wherein the cutoff unit is configured to: maintain a closed state totransmit the power input from the external power source to the inputunit, and change to an open state to cut off the power input from theexternal power source based on sensing a high voltage that is greaterthan a predetermined reference level.
 3. The compressor controlapparatus of claim 1, wherein the plurality of switching modulescomprise three pairs of switching modules, each pair of switchingmodules comprising two switching modules connected to each otherelectrically in series.
 4. The compressor control apparatus of claim 1,wherein the plurality of switching modules comprise: a first upper armswitching module, a second upper arm switching module, and a third upperarm switching module that are connected to an anode end of the inputunit; and a first lower arm switching module, a second lower armswitching module, and a third lower arm switching module that areconnected to a cathode end of the input unit, wherein the first upperarm switching module and the first lower arm switching module areconnected to each other electrically in series, wherein the second upperarm switching module and the second lower arm switching module areconnected to each other electrically in series, and wherein the thirdupper arm switching module and the third lower arm switching module areconnected to each other electrically in series.
 5. The compressorcontrol apparatus of claim 1, wherein the control unit is configured to:determine whether or not the operation of the motor is stopped based onthe cutoff unit being opened to cut off the power input from theexternal power source; and based on a determination that the operationof the motor is stopped, control the switching operation to dischargethe residual charge.
 6. The compressor control apparatus of claim 1,wherein the control unit is configured to: control the switchingoperation to discharge the residual charge based on the operation of themotor being stopped for a duration greater than a preset standby timeperiod.
 7. The compressor control apparatus of claim 2, wherein thepreset control criterion comprises an operation of at least two of theplurality of switching modules to control the switching operation. 8.The compressor control apparatus of claim 1, wherein the plurality ofswitching modules comprise a plurality of upper arm switching modulesconnected to an anode end of the input unit and a plurality of lower armswitching modules connected to a cathode end of the input unit, andwherein the control unit is configured to: control the switchingoperation of one of the plurality of upper arm switching modules and oneor more of the plurality of lower arm switching modules other than onelower arm switching module connected to the one of the plurality ofupper arm switching modules to thereby discharge the residual charge. 9.The compressor control apparatus of claim 8, wherein the control unit isconfigured to: control the switching operation of the one of theplurality of upper arm switching modules and the one or more of theplurality of lower arm switching modules to define a discharge pathbetween the input unit and the motor through the one of the plurality ofupper arm switching modules and the one or more of the plurality oflower arm switching modules to thereby discharge the residual chargethrough the defined discharge path.
 10. The compressor control apparatusof claim 1, wherein the control unit is configured to control theswitching operation for a preset discharge time period to discharge theresidual charge.
 11. A compressor control system, comprising: a motorconfigured to drive a compressor; and a control apparatus comprising aplurality of switching modules configured to convert a power input froman external power source to an operating power for operating the motor,the control apparatus being configured to output the operating power tothe motor to control operation of the motor based on controlling aswitching operation of the plurality of switching modules, wherein thecontrol apparatus is configured to, based on an operation of the motorbeing stopped, control the switching operation of two or more of theplurality of switching modules to thereby discharge a residual chargestored in the control apparatus.
 12. The compressor control system ofclaim 11, wherein the control apparatus is configured to: maintain aclosed state to transmit the power input from the external power sourceto the motor; change to an open state to interrupt the power input fromthe external power source based on sensing a high voltage that isgreater than a predetermined reference level; and in the open state,control the switching operation to discharge the residual charge. 13.The compressor control system of claim 11, wherein the control apparatusis configured to: stop the operation of the motor; and control theswitching operation to discharge the residual charge based on an elapseof a preset standby time period after stopping the operation of themotor.
 14. The compressor control system of claim 11, wherein theplurality of switching modules comprise a plurality of upper armswitching modules disposed at a first side of the plurality of switchingmodules and a plurality of lower arm switching modules disposed at asecond side of the plurality of switching modules, and wherein thecontrol apparatus is configured to: control the switching operation ofone of the plurality of upper arm switching modules and one or more ofthe plurality of lower arm switching modules other than one lowerswitching module connected to the one of the plurality of upper armswitching modules to thereby discharge the residual charge.
 15. Thecompressor control system of claim 14, wherein the control apparatus isconfigured to: control the switching operation of the one of theplurality of upper arm switching modules and the one or more of theplurality of lower arm switching modules to define a discharge pathbetween the control apparatus and the motor through the one of theplurality of upper arm switching modules and the one or more of theplurality of lower arm switching modules to thereby discharge theresidual charge through the defined discharge path.
 16. The compressorcontrol system of claim 11, wherein the control apparatus is configuredto control the switching operation for a preset discharge time period todischarge the residual charge.
 17. A method of controlling a compressorcontrol apparatus that includes a cutoff unit configured to interruptpower input from an external power source, an input unit configured toreceive the power input from the external power source through thecutoff unit, an inverter unit that is configured to convert an inputpower supplied from the input unit to an operating power for operating amotor of a compressor, the inverter unit including a plurality ofswitching modules configured to perform a switching operation to controlan output of the operating power to the motor, and a control unitconfigured to, by controlling the inverter unit, control a conversionfrom the input power to the operating power and the output of theoperating power, the method comprising: cutting off the power input fromthe external power source; determining a discharge condition based on anoperation of the motor; based on the discharge condition, performing adischarge control of a residual charge stored in the input unit bycontrolling the plurality of switching modules according to a presetcontrol criterion; and stopping the discharge control.
 18. The method ofclaim 17, wherein the discharge condition comprises whether or not theoperation of the motor is stopped or an operation stop time period forwhich the operation of the motor has been stopped.
 19. The method ofclaim 17, wherein the plurality of switching modules comprise aplurality of upper arm switching modules connected to an anode end ofthe input unit and a plurality of lower arm switching modules connectedto a cathode end of the input unit, and wherein performing the dischargecontrol comprises: controlling the switching operation of one of theplurality of upper arm switching modules and one or more of theplurality of lower arm switching modules other than one lower armswitching module connected to the one of the plurality of upper armswitching modules.
 20. The method of claim 17, wherein performing thedischarge control comprises performing the discharge control for apreset discharge time period.